Hey guys,

so I dumped my 04 cbr 600rr last spring and ive finally gotten all back together and took it for a ride around the block and everything seemed fine, then i took my girlfriend for a ride and we went about 10 miles and my rear brake peddle went all the way down when i tried to stop. luckily i was only 1/2 a mile away from my house so i rode it back and I shut it down and when i hit the pedal i could hear a suction like sound. then after pushing it and listening about 6 times it suddenly got hard and started working fine again.

anyone have a clue what that could be? any thoughts/suggestions wou;d be appreciated.

 

Do you have any brake fluid leaking anywhere?

Could you tell where the noise was coming from?

If you don't have any wetness around the lever, I would suggest pulling you rear caliper off and checking around the calipes piston. if there is wetness, replace the caliper.

If you heard a suction, chances are pretty good you have a seal that is failing either in the caliper or the master cylinder.